The Best Big Sister
by TheresaJoliePitt
Summary: AU One shot fic based on my story "A Sister By Blood,A Friend By Choice". Some moments of Kate and Kathie's life through out the years. You don't have to read that to understand this fic. Caskett towards the end but it's mostly a sister story. T for safety.


**_AN: One shot fic to go along with "Sister by Blood, Friend by Choice". I'm pretty sure you'll understand this fic if you haven't read it. I did my best with the ages for Kate to follow the Castle time line but since this is an AU story it shouldn't matter too much if I'm off by a year or two. Review if you'd like. Hope you enjoy! :) If I missed any spelling/grammatical mistakes I do apologize._**

Kate was 3 and a half when she was first handed her baby sister to hold, with her mother's help of course. She was only a few hours old and Kate could not wait any longer to meet her new sister. A pair of tiny blue eyes stared at her, as if she already knew she was her sister. Her mother did say that when the baby was in her tummy she could hear their voices. She let her little sister, Kathie, wrap her tiny hand around her finger. Kate smiled and she could of sworn that she saw Kathie smiled back before closing her eyes. "Can we take her home?" Kate looked at her mother when she took her back to put in her little hospital bed.

"In a few days sweetie. Believe me you might want to send her back when she wakes you up at night." Her mother teased.

Kate shook her head. "Nope, she's my sister," Kate said proudly as she pointed to the "I'm a big sister" sticker the nurse gave her.

Johanna and Jim both smiled at their daughter. "You'll be a good sister, Katie" Jim said before looking down at his sleeping newborn.

"I know," Kate smiled proudly.

Xxxxxxxxx

6 year old Kate was in her room, playing with her stuff animals after getting home from 1st grade, when she heard a knock on the door. She went over to the door and opened it up to reveal a smiling ,blue eyed 3 year old girl, holding a blanket. Clearly, she had just woken up from her nap.

"Katie! Home!" She hugged her older sister.

Kate smiled as she hugged her younger sister. "Wanna play with me?"

Kathie nodded. "Color?" Kate nodded and led her sister over to her desk to color. She got out the crayons, coloring books, and construction paper. Kathie took a piece of pink paper and a blue crayon. Kathie drew a few lines and large not perfect circles. She tried writing her name and Kate's under the blobs but she didn't know how. She slid the paper over to Kate. "Katie. You and me." She pointed at the blue blob as her and the purple one as Kate.

Kate smiled. "You drew this for me?"

Kathie nodded. "For best big sister."

xxxxx

16 year old Kate and 13 year old Kathie were a handful to say the least. Kate was growing out of the girly phase and slowly moving into her wild child phase and Kathie was still in that phase where she wanted to be her big sister. Kathie saw Kate sneak in past her curfew and Kathie wanted to do it too. That Friday night was not a pleasant one at the Beckett house hold. Both Kate and Kathie were caught sneaking in past curfew. They were both grounded and sent to their rooms for the rest of the weekend.

Kathie was just about in bed when she heard her door open. It was Kate. She closed the door behind her and headed over to the other side of Kathie's bed. "Why were you out so late?"

"Cause I want to be like you."

Kate hugged her sister. "You don't need to be like me. You're perfect the way you are Kathie. Be you."

Kathie leaned her head against her sister's shoulder. "Can we have a sleepover tonight?"

Kate smiled. "I think that sounds like a good idea. Just as long as you don't hog the covers."

"You're the one that hogs the covers and you just told me to not be like you. You're condra..." she tried to remember the word she had heard her teacher use. "Contradicting yourself!"

Kate smiled seeing how proud her sister was in remembering the big, new, word. "Where did you learn that from?"

"School. Bet you don't know what it means."

Kate pretended to be dumb. "Not a clue."

Kathie smiled, being proud that she knew something Kate didn't. "I'll teach you it tomorrow. Sleep time now." She yawned and closed her eyes.

"Night Kathie." Kate turned off the light and laid her head down on the pillow, being careful not to move Kathie off of her shoulder. Even if she was becoming a wild child she would always be the best big sister.

Xxxx

18 year old Kate and 15 year old Katie were on Kate's high school football field for her graduation. Kate was about to give her speech and Kate had told Kathie that she had a surprise for her. Kate looked into the crowd and saw her sister's smiling face. That was all she needed to gain her confidence.

"I have learned a lot through my high school career and have changed since I was a freshman. A lot of us have. But there is one thing that has never changed, I'm still the best big sister." She smiled at Kathie. "And that is what got me through my toughest day in high school. I had to be that best big sister and I couldn't let her down. Without my little sister I wouldn't be here today giving this speech. What I am trying to say, besides that my little sister is amazing, is that you need your family. Most of us are heading off to college and leaving our families behind so don't forget them while you're away. Remember the annoying phone calls everyday are due to because they care. They will always be there when you're stressing for an exam or just feeling homesick. I know my sister will be calling me everyday but I wouldn't trade it for the world. Getting an education is important but family is forever."

It wasn't the classic graduation speech but it was perfect. Kathie of course was the one to clap the loudest for her sister when the speech was over and when her name was called to receive her diploma.

When they returned home Kathie knocked on her sister's door. "Kate, I got you a present."

Kate opened up the door to see Kathie hold a large rectangle box. She gave her sister a look. "This isn't a trick is it? Cause after that speech I gave..."

Kathie smirked and shook her head no. "No, open it".

Kate undid the ribbon and took the top off of the box to reveal Richard Castle's first book. Why was she giving her this? She should be giving it to their mother. She's the one that liked him.

Kathie smirked at her reaction. "Open the flap."

Kate did and saw the front page signed with a message. _"To Kate, Congratulations on graduating! Your sister says you're not a big fan. She thinks you're just in denial and you really are a fan. I'm hoping that she is right and you're not going to use my book to make a bonfire, that is what Patterson's books are for. - Richard Castle." _

"Really Kathie? You couldn't have gotten me a new bike helmet?"

Kathie smirked "Nope. Enjoy" She hugged her sister. "Have fun tonight. Don't forget you still have to be the best big sister even when I'm not around." She winked before heading to her room.

Xxxxx

19 year old Kate and 16 year old Kathie stood underneath the same umbrella as they said goodbye to their mother. Kathie's head was resting on her sister's shoulder. Both of them were trying not to cry for the sake of each other and their father. Once the last rose was placed on the coffin they started walking to their cars one by one. Kathie, Kate, and Jim were the last to leave. Once they were home Kate knocked on Kathie's door before entering. She saw her curled up in a ball on her bed, crying.

Kate went over to her and brought her sister into her arms, where they cried together. They had lost their mother and they needed to just let the tears fall. Before Kathie fell asleep she whispered to Kate "Thanks for being here, best big sister."

xxxx

20 year old Kate was reading Richard Castle's book that Kathie had gotten her for her graduation. She never bothered reading it but her mother did. Johanna said it was better than his first. 17 year old Kathie came home from school to see her sister reading the book and smiled. She knew she was doing it to be closer to their mother and try to find out what her mother liked these books so much but it still made Kathie smiled. She poked her sister on her shoulder and smirked when Kate's head moved to look up at her.

"How's the book?"

"Shut up." Kate smiled.

"Yea, totally in denial. I was right!" Kathie smiled as she happily skipped towards her room.

Kate rolled her eyes. Okay, so maybe she was a fangirl. She wasn't going to admit that out loud though.

xxxx

21 year old Kate and 18 year old Kathie stood on the football field once again. This time without their mother and this time Kathie was the one graduating. Kathie didn't give a speech but Kate was the loudest one on the field to cheer for her sister when her name was called. Kathie smiled at her sister before heading back to her seat.

When they arrived back home Kathie was in her room. She didn't want to do the whole project graduation thing. Kate knocked on her sister's door before entering with the same box she had given her two years ago. "Is that a book?"

"Open it and find out." Kate flopped onto her sister's bed which made Kathie smiled. She undid the ribbon and opened it revealing Richard Castle's new book that was not supposed to be released for a week. She also noticed the signature on the cover. "How did you get this?"

"Won it on his website." She smiled.

Kathie shook her head and smiled. "You're such a fangirl, Katie." She put the book aside. "But it still makes you the best big sister."

xxxx

23 year old Kate and 20 year old Kathie saw each other for the first time since Kathie went to Florida for school. Their communication was slowly dying. Kate was trying to solve their mother's murder and Kathie was determined to finish school early. No matter how determined Kathie was she wasn't going to miss her sister graduate from the police academy. Plus she had a really great story to tell her sister when the ceremony ended.

When they embraced in a hug it was like they hadn't parted their separate ways. When they pulled away Kathie smiled at her. "Congrats big sister! You're never going to believe what I saw last night outside my hotel."

"What?" Kate gave her a confused look

"A naked man on a police horse. I can see why you want to join the force." Kathie smirked which made Kate roll her eyes.

"Could you see who it was?"

Kathie shook her head. "No, but from behind it was a nice view."

xxx

25 year old Kate and 22 year old Kathie were not together during Kathie's college graduation. Kathie missed the loud whistling and screaming coming from a far. But her dad was there clapping for her and extremely proud. This was the first time that Kate didn't live up to the best big sister title. And it was all because she was making sure she was protected. She didn't need protection from the bad guys, she needed her sister.

Xxx

31 year old Kate called up her 28 year old sister Kathie after work. She had not spoken to her sister in over 5 years, if you didn't count the 4 minute birthday calls. "Come on, Kathie pick up!"

"Jesus, Kate it only rang three times! What's so important?"

"Guess who is my new 'partner'"

"Since when do you have a partner?"

"Since Richard Castle decided her wanted to shadow me."

"I bet that's not the only thing he wants to do to you." She smirked.

"Kathie!"

"What? You could brag about it on his website. What's your username again? Castle..."

"Not important what my name is on there! And that is never going to happen!"

"Yea, I give it a year before you act on your urges."

"You know I didn't call you to discuss when I'm going to have sex with Richard Castle."

"No, you just called to brag about it that you have a famous writer as your partner because you can't tell this to anyone else."

"...Alright maybe...but I wouldn't use the word brag."Kathie rolled her eyes and laughed a bit. "Don't shoot him Kate. What kind of example would you be if you're the big sister shooting her 'partner'?"

Kate smirked. "The kind that is going to start calling her little sister when it's not her birthday."

Kathie smiled. "If you start calling on holidays that doesn't count."

"Well I can't help it if it's a holiday and something interesting happens at work."

"Well with Castle working there now I have a feeling your days are going to get a lot more interesting."

xxx

35 year old Kate entered 32 year old Kathie's apartment with a bright smile on her face. Kathie looked confused. "What's with you?"

Kate showed her hand that was supporting a new diamond ring to her sister.

"Oh my. Mr. Castle has good taste! Congrats Kate!" She hugged her sister.

"Thank you. Now obviously, this is a stupid question but...will you be my maid of honor?"

Kathie smiled. "Anything for my favorite big sister. Just don't turn into bridezilla or I'm going to have to hurt you."

Kate rolled her eyes. "Please, if anyone in the family has bridezilla in her it's you."

"Me!"

"Yes, you were the one dragged mom all over town looking for the perfect flower girl dress for Aunt Sue's wedding when you were five. Nothing was flower girl enough for you, whatever that meant."

"I just wanted to outshine you." She smirked. "Don't worry, I'll pick the puke green bridesmaid dress so I can look horrible on your special day."

"That won't be necessary...I was thinking purple." She smiled.

Xxx

36 year old Kate was looking at herself in the mirror as 33 year old Kathie tied the back of her wedding dress. "You look gorgeous Katie. Castle won't know what to do with himself." She smiled, and so did Kate.

"Thank you." She touched their mother's ring that was around her neck and looked at Kathie in the mirror. "Are we ready?"

"Not quite. I need to give you your something old, new, blue, and borrowed."

"Kathie, I told you I..."

"Don't believe in tradition. I know! But Rick made me. He said he wanted to make sure there was no bad luck by breaking tradition." She pulled out the small bag and started pulling out the items. "Killing two birds with one stone with this one. Your old, light blue butterfly earrings you leant me."

"You said you lost them!"

"I said that cause I wanted to keep them," She smirked and Kate glared at her before putting them on.

Kathie took out the next item. She pulled out a new bracelet. It was part of a set. She handed one to Kate before putting the other one on. "Read it."

She saw the word best and saw that Kathie's said sister. "Aren't we a little old for these?"

"Nope." Kathie smiled before taking out the last item. She took out a small hair clip that had three pearls on it. "The hair clip you always eyed whenever we were younger. I'm letting you borrow it. But you better not lose it like I did with your earrings" She smiled and so did Kate.

Kate hugged her sister. "Thank you."

"That's what the best little sister does." Kathie smiled. "Come on, Just about Mrs. Castle. You have guests waiting to see you marry your fiance." She pulled away from the hug and helped Kate exit the room.

Xxx

37 year old pregnant Kate was looking at 34 year old Kathie in the mirror, making sure she was perfect before she walked down the aisle. "You look beautiful, Kathie."

Kathie smiled. "As do you. Is my little nephew still playing soccer in your tummy?"

"I think he's done practicing for now."

She heard a knock on the door and saw Rick enter. Both Becketts gave him a soft smile. "You two look great. But you should know your future husband is a nervous wreck."

Kathie laughed. "So were you if I recall on your wedding day."

"What? You didn't tell me that." Kate looked at both of them.

"When I went to use the bathroom really quick I saw him outside pacing and mumbling to himself. So we took a shot to calm our nerves." Kathie did her best to hid her smirk.

"You two were drunk before the ceremony!"

"I didn't say drunk." Kathie laughed not being able to keep her cover anymore. "I'm just kidding. Both of us were perfectly sober."

Castle wrapped an arm around his wife's waist and pulled her closer, reassuring her that he did not have to be drunk to marry her. "I'd remary you again in a heartbeat." He kissed the top of her head.

"Lets get done with my wedding first, then you two can go renew your vows."

Castle left the room and Kate grabbed her sister's hand.

"What's wrong, Kate?" Kathie asked.

"I think I just felt a contraction."

"Is this your first one?"

"I had one like fifteen minutes ago after I used the bathroom."

"Oh boy. Well he definitely has your timing." Kate glared. "Come on lets get you to the hospital."

"No, we're getting you married!"

"Kate..."

"No questions. They're fifteen minutes apart. We'll be fine."

"As soon as I seal the deal with a kiss we're going, you hear me!"

"Yes, big sister." Kate said sarcastically.

"Someone has to be the responsible one."

Kathie walked down the aisle with Jim to meet her soon to be husband. Kate had never been so grateful that Kathie asked for the short ceremony because by the time she said I do her contractions were about five minutes apart. Kathie kissed her husband and instead of walking down the aisle with her husband she rushed her sister down it. Everyone was confused with what was going on. "Castle! It's time!" Kate said before letting out a groan, caused by one of her contractions.

With that Castle, Alexis, Martha, Esposito, Lanie, Ryan, Kathie's husband, and Jim left from their spot and rushed over to the two women who were heading into the limo.

One of the privileges of having a cop in labor was that they were able to break a few traffic laws. The little guy entered the world in no time. Kathie got one of the stickers Kate wore 34 years ago from the nurse stations and placed it on Alexis's dress. "Just in case they had trouble verifying who was older." She smirked and Alexis smiled.

They went inside Kate's room, who was holding the tiny baby, wrapped up in a blue blanket, in her arms. Kathie went over to Kate to see her nephew who was staring at his mother and now looking at his aunt. Both Kathie and Kate smiled. "Sorry about ruining your special day Kath" She took her sister's hand in one of hers.

Kathie shook her head and smiled. "Are you kidding! This is the best wedding present you could of given me! Besides, it makes the day even more memorable." She squeezed her sister's hand as she noticed the little guy had fallen asleep. Alexis had helped Kate to transfer him to his little hospital bed.

"You think she'll be a better big sister than me?"

"Definitely." Kathie smirked as she teased. But in all reality they knew that definitely meant no because no one could compare to Kate in Kathie's eyes. She was the best big sister she could have asked for.

xxx

40 year old Kate was telling her 3 year old soon the story about his 37 year old aunt. "And that is is Aunt Kathie got me my first book that Daddy wrote."

Her son look up from where he was resting on her shoulder. "Does Daddy know?"

"No, this will be our secret." Kate kissed her son's head before tucking him in for the night. She headed out of the room and towards the living room where she knew her husband would be. She sat down next to him before she leaned back into his arms.

"What story did you tell him this time?"

Kate smirked. "It's a secret."

"Secrets secrets are no fun unless you share them with everyone," Castle said before placing a kiss on her neck.

Kate rolled her eyes. "Just a story about how I first met you."

"You told him about how you basically arrested me at my book launch party?"

"I told him I was gentle with the handcuffs." She smirked before she placed a kiss on his lips.

"Really you two? Putting the kid to bed does not mean you can go at it on the sofa...especially when you know I'm coming over."

Kate pulled away to roll her eyes at her sister. "Kathie, did Kate meet me before that night at the book launch?" Kate gave her sister a look that said shut up or that Chinese food I promised you will be poisoned.

Kathie laughed and took her daughter from her husband's arms, seeing that she was starting to get fussy and she didn't want to wake up her little nephew. "That's for Kate to tell and you to probably never find out." Kate smiled. Kathie was the best little sister ever.


End file.
